Valve for pneumatic tools



June 5, 1945. R. c. WILES v VALVE FOR PNEUMATIC TOOLS Original Filed May 5, 1942 No. ommm mw n QM. Rmx

vA ltorneys 'l Patented June 5, 1945 -jfoN1TEo` t STATES PATENT OFFICE w 2,377,354; VALVEronrmrnlua'rrcrootsV n l Robert Clough Wiles, `Heaton, Newcastle-on- Tyne, England, assignor tdCharlesgCroftonand Company` (Engineers) limited, Wallsentleon,` 1 r Tyne, England'a Britishcllmpany Original application May l5, "1942,3Serial No. l

i 441,847. Divided and this application February 18, 1944, Serial No. May"19."1941 i this valve including a `iilter` and the valve `body being formed with a by-pass port and a movable y part thereof with an exhaust passage, so that when the saidmovable part is in a certainposition` air is admitted to a part of the inlet pipe beyond soisims.l (origea-"esoN` the filter, through which the air returns and es-` capes through the exhaust passage, thereby cleaning the'lter. w M y `The present invention has `for `its object to provide improved facilities for cleaning the filter in that type of compressed air valvein which the movable member is a `sleeve `surrounding a tubular valve body. interposed in the pipe line, the

sleeve ybut is uncovered as a consequence of the movement of the sleeve to the position in which it admits compressed air to the aforesaid port. Referring `tothe accompanying drawing: Figures 1, 2 and 3 are longitudinal sectional views of a valve according to this invention, showing the moving parts, thereof in three different` positions. i i

Figure 4 is a plan view of a part ofFigure 1. Referring to the drawing, the valve body 46 has an extension 9|] through which airunder pressure enters, and, after passing the valves the air reaches the outlet 60 suitably connected to the pneumatic tool to be operated (not Shown) `The mainair supply valve is of the mushroom type, consisting of the valve head 42 seated against `l i that end of a socket member 44 within the valve body 46 which faces `the incoming air, the other `end of this socket member being covered by a disc 48 of wire gauze constituting the filter. The valve head 42 is joined by a stem 5l) to a cylindrical plug 52 sliding within the socket member 44. The end of this plug 52 remote from the valve head is formed with a central bore 54 com- A LG municating with a wide groove 56 in the side of `member44. Thus, when the valve head 42 is `moved away from the seating at the end of the 522,832. y In GreatBritain socket 44,` air can nowfpast the valve head through the groove 56 and thecentral bore54 and through V `the iilter "48 to the outlet B0 leading to thetool. .1

` Theplug 52has a pin` 62 extending` from its,`

Side through longitudinal Slots 64, BU in the Socket 44 and thevalve body respectively-,these slots permitting the plug to slide endwisebutl prevent#` ing it ,from turnin`g.- An outersleeve 68 sur;-`

'rounds and rotates uponthe valve body,`and this sleeve 6B is formedvvith a helicalslotlu engaging the extremity of the pin 62, `so that when the outer sleeve 6 8 is rotated inone direction while abutting againstthe shoulder ated, thepin isimoved endwise to raise the valve head"42 from its seat* `ing, thereby admitting air (Figure 2) fvi/"henthe` sleeve is turned inthe other direction, and is still heldf against shouldered by `spring 88, the pin is moved the other way toclose the valve, as in Figure 1; f i

Thereis a duct filter 48." This duct is formed partlyjby agroove` l2 in the outer surface of thefvalvebody which" also constitutes the port and partly by a groove 1li` in. the'outer'surface of the socket 44 inwhich plug `5,2 slides. The, twol grooves overlap andare Yplaced in communication with ons` another by a hole 'I6 in the side of the valve body, the inner end of this hole constituting a seating `for a ball 18 acting as a non-return valve. bourhood of the valve head 42 there is another hole through the sideof the valve body, on the cannotmove any further, `and so the sleeve `68` i itself moves in the endwise direction towards the right against the action of spring 88. ment brings a recess 82 inthe inner surface of the sleeve 68 into registersimultaneously with,`

the `groove 'l2 and the hole 80 so that air can pass through the hole 80, the recess 82, the groove 12, the hole 16 and the groove 14. At the same time anexhaust passage 84 inthe opposite side of the outer sleeve 68 is brought into register with a h ole 86 extending through the valve body and the socket 44 into the annular space 58 surround-` i ing' the valve stem. Thus, air is supplied to the space beyond the lter 48, returns through the filter. thereby cleaning it, through the central ,y y orfs'rnml*cross-sectioninthe` i y y valve body leadingfrorna portinthe side ofthe body to the space immediately beyond thegauze l n n In the neigh-` i bore 54 and the groove 5B in the plug, into the annular space 58 around the valve stem and out through the hole 86 and exhaust passage 84.

The non-return ball valve 18 is provided to v prevent escape of air backwards through the bywise motion of the outer sleeve 68, surrounds a Y screwed-in extension 90 of the valve body and is housed in a shell 92 iixed to the extension 90 at one end and overlying the extremity of the outer sleeve 68 at the other end. Y

`The shoulder` 94 on the valve body against which the lefthand end of the outer sleeve abuts bears. an index mark 96, and the outer sleeve 68 bears the `words open, closed, cleanfin the appropriate positions,as shown in Figure 4.

It will be appreciated that when the sleeve is set to the clean position the air has to pass through passages of restricted cross section before reachingthe filter, with the result that ,the velocity of the air in the pipe leading to the valve is restricted, being not greater than the'velocity of the ow when the tool is being operated. Consequently there is no risk of pieces of scale or other gritty particles, vwhich may be lying dormant inthe pipe, being carried into the part of the valve body beyond the iilter, from which they would be blown into the tool when the sleeve is next turned to the on position.

I claim:

1. A valve for controlling the supply of compressed air to pneumatic tools comprising in combination a valve body of circular cross section having passages therein for the entry and outlet of air, a valvernember and a seatingtherefor in said'valve body, a sleeve surrounding said valve body with a diagonal slot therein, a pin connected to said valve member projecting throughl a lor1giA tudinal slot in the' valve body and into the diagonal slot in' said sleeve, said valve member having a head adapted to close upon a seating in said valve body when the valve member is moved in one direction by the turning of said sleeve, a filter within the valve body in the outlet portion thereof, a passage of restricted cross-section in said valve body leading to an outlet beyond said lter, and ports in the valve body and the sleeve adapted in one position of said sleeve in which the valve member is closed on its seating, to connect the 'entry side of the valve body to said passage of restricted cross-section, and to connect the other side of said valve body between the iilter and the Valve member tothe atmosphere.

l2. A valve according to claim 1 having said sleeve normally bearing against a shoulder on the valve body preventing longitudinal movement of said sleeve in one direction, spring means tending to press said sleeve against said shoulder but permitting movement of said sleeve away from said shoulder when the sleeve lis turned beyond the position for closing said valve member-on its seating, said ports in the valve body and sleeve being so positioned as to be brought into register by movement of said sleeve away -from said shoulder on the valve body. l

3. A valve for controlling the supply `of compressed air to pneumatic tools comprising in combination a valve body of circular form with longitudinal passages therein fory entry andoutlet' of` air, a longitudinally movablefvalve member and a seating therefor in said valve body, a filter within said valve body through which air normally passes after passing said valve member, a sleeve surrounding said valve body and normally bearing at lone end against a shoulder on said valve body, a spring and means for supporting same'V on the valve body in a position to bear against the other end of said sleeve, means oper.- able on turning of said sleeve in one direction for raising said valve member from its seating while said sleeve bears against said shoulder, and for causing said sleeve lto move longitudinally against the action of said spring'when turned in the oppositedirection, and ports and passages in said rvalve body and said sleeve adapted as a consequence of `such longitudinal movements ofsaid sleeve to y permit a restricted reverse flow of air throug said iilter and Yout to the atmosphere.

ROBERT CLOUGH 

